We are undertaking a survey of bacterial low molecular weight thiols in connection with our studies on actinothione in tuberculosis (see attached abstract). We have purified two thiols as their bimane derivatives from Chromatium vinosum which are structurally related to glutathione. Mass spectrometry will be used to determine the structure using the molecular ion mass of these thiols. We have had previous success in thiol structure determination using the bimane derivwative of U17 from Streptomyces, UCSF project no. 351.